1. Field of the Invention
The present invention relates to ratchets and, more particularly, to heavy duty ratchets.
2. Description of Related Prior Art
Ratchets for use with cords of various types have been commercially available for a period of years. U.S. Pat. Nos. 6,068,242, 6,092,791, and Des. 362,614 are representative and are incorporated herein by reference. A ratchet of this type includes a housing having a hook or like member for attaching the ratchet to an anchor point. A spool within the housing supports a cord partially wrapped thereabout and extending from within the housing. The spool includes a ring-like arrangement of a plurality of teeth engageable by a pawl to prevent rotation of the spool in one direction. The opposed sides of the spool contacting the cord partially wrapped thereabout includes a plurality of ridges to minimize slippage of the cord on the spool. Upon exerting a pulling force on a first length of the cord extending from within the ratchet, the spool is caused to rotate to draw the second length of cord extending from the ratchet into the ratchet. Thereby, tension can be applied to the second length of cord as the first length of cord is pulled. The resulting tension force exerted on the second length of cord will tend to wedge the cord within the spool due to the ridges in the spool. Thereby, slippage of the cord about the spool due to the tension force exerted is essentially eliminated. To release the tension force, the pawl is pivoted out of engagement with the teeth to permit the spool to freely rotate in either direction.
Some variations of the above-described ratchet and those shown in the above referenced patents have been developed. However, the amount of tension force that can be applied has been essentially limited by the degree of pulling force manually exerted upon the free end of the cord. Usually, the tension force is 100 or so pounds.